106 lines
3.3 KiB
Markdown
106 lines
3.3 KiB
Markdown
---
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layout: "docs"
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page_title: "Configuring Outputs"
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sidebar_current: "docs-config-outputs"
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description: |-
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Outputs define values that will be highlighted to the user when Terraform applies, and can be queried easily using the output command. Output usage is covered in more detail in the getting started guide. This page covers configuration syntax for outputs.
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---
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# Output Configuration
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Outputs define values that will be highlighted to the user
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when Terraform applies, and can be queried easily using the
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[output command](/docs/commands/output.html). Output usage
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is covered in more detail in the
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[getting started guide](/intro/getting-started/outputs.html).
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This page covers configuration syntax for outputs.
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Terraform knows a lot about the infrastructure it manages.
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Most resources have attributes associated with them, and
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outputs are a way to easily extract and query that information.
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This page assumes you are familiar with the
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[configuration syntax](/docs/configuration/syntax.html)
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already.
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## Example
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A simple output configuration looks like the following:
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```hcl
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output "address" {
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value = "${aws_instance.db.public_dns}"
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}
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```
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This will output a string value corresponding to the public
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DNS address of the Terraform-defined AWS instance named "db". It
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is possible to export complex data types like maps and lists as
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well:
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```hcl
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output "addresses" {
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value = ["${aws_instance.web.*.public_dns}"]
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}
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```
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## Description
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The `output` block configures a single output variable. Multiple
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output variables can be configured with multiple output blocks.
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The `NAME` given to the output block is the name used to reference
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the output variable.
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Within the block (the `{ }`) is configuration for the output.
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These are the parameters that can be set:
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- `value` (required) - The value of the output. This can be a string, list, or
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map. This usually includes an interpolation since outputs that are static
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aren't usually useful.
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- `description` (optional) - A human-friendly description for the output. This
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is primarily for documentation for users using your Terraform configuration. A
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future version of Terraform will expose these descriptions as part of some
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Terraform CLI command.
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- `depends_on` (list of strings) - Explicit dependencies that this output has.
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These dependencies will be created before this output value is processed. The
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dependencies are in the format of `TYPE.NAME`, for example `aws_instance.web`.
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- `sensitive` (optional, boolean) - See below.
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## Syntax
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The full syntax is:
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```text
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output NAME {
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value = VALUE
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}
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```
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## Sensitive Outputs
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Outputs can be marked as containing sensitive material by setting the
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`sensitive` attribute to `true`, like this:
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```hcl
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output "sensitive" {
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sensitive = true
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value = VALUE
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}
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```
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When outputs are displayed on-screen following a `terraform apply` or
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`terraform refresh`, sensitive outputs are redacted, with `<sensitive>`
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displayed in place of their value.
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### Limitations of Sensitive Outputs
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- The values of sensitive outputs are still stored in the Terraform state, and
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available using the `terraform output` command, so cannot be relied on as a
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sole means of protecting values.
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- Sensitivity is not tracked internally, so if the output is interpolated in
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another module into a resource, the value will be displayed.
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